#!/bin/bash
#
# This is SORT OF LIKE an X session, but not quite.  You get a command as the
# first argument (it could be multiple words, so run it with "eval").  As a
# special case, the command can be:
#  default - Run the appropriate Xclients startup (see the code below)
#  custom - Run ~/.xsession and if that's not available run 'default'
#
# (Note that other arguments could also follow, but only the command one is
# right now relevant and supported)
#
# The output is ALREADY redirected to .xsession-errors in GDM.  This way
# .xsession-errors actually gets more output such as if the PreSession script
# is failing.  This also prevents DoS attacks if some app in the users session
# can be prodded to dump lots of stuff on the stdout/stderr.  We wish to be
# robust don't we?  In case you wish to use an existing script for other DM's,
# you can just not redirect when GDMSESSION is set.  GDMSESSION will always
# be set from gdm.
#
# Also note that this is not run as a login shell, this is just executed.
# This is why we source the profile files below.
#
# based on:
# $XConsortium: Xsession /main/10 1995/12/18 18:21:28 gildea $

command="$@"

# this will go into the .xsession-errors along with all other echo's
# good for debugging where things went wrong
echo "$0: Beginning session setup..."

# temporary storage of error messages
ERR=$(mktemp --tmpdir gdm3-config-err-XXXXXX)

source_with_error_check () {
  CONFIG_FILE="$1"
  . "$CONFIG_FILE" 2>"$ERR"
  if [ -s "$ERR" ]; then
    . /etc/gdm3/config-error-dialog.sh
  fi
  cat "$ERR" >&2
  truncate -s 0 "$ERR"
}

# First read /etc/profile (resp. /usr/etc/profile) and .profile
if [ -f /etc/profile ]; then
  source_with_error_check /etc/profile
elif [ -f /usr/etc/profile ]; then
  source_with_error_check /usr/etc/profile
fi
if [ -f "$HOME/.profile" ]; then
  source_with_error_check "$HOME/.profile"
fi
# Second read /etc/xprofile (resp. /usr/etc/xprofile)  and .xprofile for X specific setup
if [ -f /etc/xprofile ]; then
  source_with_error_check /etc/xprofile
elif [ -f /usr/etc/xprofile ]; then
  source_with_error_check /usr/etc/xprofile

fi
if [ -f "$HOME/.xprofile" ]; then
  source_with_error_check "$HOME/.xprofile"
fi

# Translation stuff
if [ -x "/usr/libexec/gdmtranslate" ] ; then
  gdmtranslate="/usr/libexec/gdmtranslate"
else
  gdmtranslate=
fi

# Note that this should only go to zenity dialogs which always expect utf8
gettextfunc () {
  if [ "x$gdmtranslate" != "x" ] ; then
    "$gdmtranslate" --utf8 "$1"
  else
    echo "$1"
  fi
}

OLD_IFS=$IFS

gdmwhich () {
  COMMAND="$1"
  OUTPUT=
  IFS=:
  for dir in $PATH
  do
    if test -x "$dir/$COMMAND" ; then
      if test "x$OUTPUT" = "x" ; then
        OUTPUT="$dir/$COMMAND"
      fi
    fi
  done
  IFS=$OLD_IFS 
  echo "$OUTPUT"
}

zenity=`gdmwhich zenity`

# Note: ~/.xsession-errors is now done in the daemon so that it
# works for ALL sessions (except ones named 'Failsafe')

# clean up after xbanner
freetemp=`gdmwhich freetemp`
if [ -n "$freetemp" ] ; then
	"$freetemp"
fi

userresources="$HOME/.Xresources"
usermodmap="$HOME/.Xmodmap"
userxkbmap="$HOME/.Xkbmap"

if [ -f /etc/X11/Xresources ]; then
    sysresources=/etc/X11/Xresources
else
    sysresources=/usr/etc/X11/Xresources
fi

if [ -f /etc/X11/Xmodmap ]; then
    sysmodmap=/etc/X11/Xmodmap
else
    sysmodmap=/usr/etc/X11/Xmodmap
fi

if [ -f /etc/X11/Xkbmap ]; then
    sysxkbmap=/etc/X11/Xkbmap
else
    sysxkbmap=/usr/etc/X11/Xkbmap
fi

rh6sysresources=/etc/X11/xinit/Xresources 
rh6sysmodmap=/etc/X11/xinit/Xmodmap 

# merge in defaults
if [ -f "$rh6sysresources" ]; then
    xrdb -nocpp -merge "$rh6sysresources"
fi

if [ -f "$sysresources" ]; then
    xrdb -nocpp -merge "$sysresources"
elif [ -d "$sysresources" ]; then
    # directory of Xresources files on Debian/Ubuntu
    for i in `ls "$sysresources"` ; do
        if [ -r "$sysresources/$i"  -a -f "$sysresources/$i" ] && expr "$i" : '^[[:alnum:]_-]\+$' > /dev/null; then
            xrdb -nocpp -merge "$sysresources/$i"
        fi
    done
fi

if [ -f "$userresources" ]; then
    xrdb -nocpp -merge "$userresources"
fi

# merge in keymaps
if [ -f "$sysxkbmap" ]; then
    setxkbmap `cat "$sysxkbmap"`
    XKB_IN_USE=yes
fi

if [ -f "$userxkbmap" ]; then
    setxkbmap `cat "$userxkbmap"`
    XKB_IN_USE=yes
fi

#
# Eeek, this seems like too much magic here
#
if [ -z "$XKB_IN_USE" -a ! -L /etc/X11/X ]; then
    if grep '^exec.*/Xsun' /etc/X11/X > /dev/null 2>&1 && [ -f /etc/X11/XF86Config ]; then
       xkbsymbols=`sed -n -e 's/^[     ]*XkbSymbols[   ]*"\(.*\)".*$/\1/p' /etc/X11/XF86Config`
       if [ -n "$xkbsymbols" ]; then
           setxkbmap -symbols "$xkbsymbols"
           XKB_IN_USE=yes
       fi
    fi
fi

# xkb and xmodmap don't play nice together
if [ -z "$XKB_IN_USE" ]; then
    if [ -f "$rh6sysmodmap" ]; then
       xmodmap "$rh6sysmodmap"
    fi

    if [ -f "$sysmodmap" ]; then
       xmodmap "$sysmodmap"
    fi

    if [ -f "$usermodmap" ]; then
       xmodmap "$usermodmap"
    fi
fi

unset XKB_IN_USE

xhost +si:localuser:`id -un` || :

# run all system xinitrc shell scripts.
if [ -d /usr/etc/X11/xinit/xinitrc.d ]; then
    for i in /usr/etc/X11/xinit/xinitrc.d/* ; do
	sname=$(basename "$i")
        test -x "/etc/X11/xinit/xinitrc.d/$sname" && continue
        if [ -x "$i" -a ! -d "$i" ]; then
            . "$i"
        fi
    done
fi
if [ -d /etc/X11/xinit/xinitrc.d ]; then
    for i in /etc/X11/xinit/xinitrc.d/* ; do
        if [ -x "$i" -a ! -d "$i" ]; then
	    . "$i"
        fi
    done
fi

# run /etc/X11/Xsession.d/
OPTIONFILE=/etc/X11/Xsession.options
USERXSESSION=$HOME/.xsession
USERXSESSIONRC=$HOME/.xsessionrc
ALTUSERXSESSION=$HOME/.Xsession
if [ -d /etc/X11/Xsession.d ]; then
    for i in `ls /etc/X11/Xsession.d/` ; do
        if [ -r "/etc/X11/Xsession.d/$i"  -a -f "/etc/X11/Xsession.d/$i" ] && expr "$i" : '^[[:alnum:]_-]\+$' > /dev/null; then
	    . "/etc/X11/Xsession.d/$i"
        fi
    done
fi

if [ "x$command" = "xdefault" ] ; then
  if [ -x "$HOME/.Xclients" ]; then
    command="$HOME/.Xclients"
  elif [ -x /etc/X11/xinit/Xclients ]; then
    command="/etc/X11/xinit/Xclients"
  elif [ -x /etc/X11/Xclients ]; then
    command="/etc/X11/Xclients"
  else
    if [ -n "$zenity" ] ; then
	disptext=`gettextfunc "System has no Xclients file, so starting a failsafe xterm session.  Windows will have focus only if the mouse pointer is above them.  To get out of this mode type 'exit' in the window."`
      "$zenity" --info --text "$disptext"
    else
      echo "$0: Cannot find Xclients"
    fi
    exec xterm -geometry 80x24+0+0
  fi
fi

# add ssh-agent if found
sshagent="`gdmwhich ssh-agent`"
if [ -n "$sshagent" ] && [ -x "$sshagent" ] && [ -z "$SSH_AUTH_SOCK" ]; then
    command="$sshagent -- $command"
elif [ -z "$sshagent" ] ; then
    echo "$0: ssh-agent not found!"
fi

echo "$0: Setup done, will execute: $command"

eval exec $command

echo "$0: Executing $command failed, will run x-terminal-emulator"

if [ -n "$zenity" ] ; then
	disptext=`gettextfunc "Failed to start the session, so starting a failsafe terminal session.  Windows will have focus only if the mouse pointer is above them.  To get out of this mode type 'exit' in the window."`
	"$zenity" --info --text "$disptext"
fi

exec x-terminal-emulator -geometry 80x24+0+0
